Ubuntu errors with PCIPassthrough with GPUs

I have a system with 8GPUs in a single box. We are trying to allow VMs to request access to GPU resources via this box.

I know that with PCI Passthrough you can't share a device with a VM (e.g. deviceid1 <-> 1 VM, or deviceid2 & deviceid3 <-> 1VM).

I have successfully been able to get the system to have 1 GPU <-> 1 VM with the CentOS image from here (http://docs.openstack.org/image-guide...). However, if I try to use the Ubuntu 14.04 image it doesn't attach properly.

I see the following in dmesg. [ 0.638033] pci 0000:00:05.0: unknown header type 7f, ignoring device